Probes and catheters for insertion into the vascular system of a patient must be kept sterile during transit, storage and the ensuing medical procedure. Probes and catheters are typically enclosed in a sterile package at the manufacturer's plant and shipped to the user in the sterile package. When the probe or catheter is to be used, it is removed from the package and inserted into the patient's vascular system using conventional medical techniques. Unfortunately, after being removed from the sterile package, there is some risk of loss of sterility through contact with non-sterile objects. This risk is made somewhat greater by the elongated, flexible nature of probes and catheters.